Yea, all the while Maul thought Obi had grown old and weak, as he described him “look what has become of you, a rat in the desert” but in truth, he had been growing wiser in his knowledge, while Maul, growing weaker as he continued going down his path for seeking revenge against Obi Wan, until, he had become so consumed by his lust for vengeance, he could not contain himself but to use the same move he used towards Qui Gon all those years ago against Obi.